KR20200109153A - Secondary battery - Google Patents

Abstract

The present invention relates to a secondary battery with an improved structure and, more specifically, to a secondary battery comprising: an electrode assembly; a support case having a plurality of through holes formed on at least one surface thereof, and provided to surround the electrode assembly; and a foam member positioned between the support case and the electrode assembly.

Description

Secondary battery {SECONDARY BATTERY}

The present invention relates to a secondary battery.

Recently, a lithium secondary battery capable of charging and discharging and having a high energy density and power density while being light and capable of being charged and discharged has been widely used as an energy source of wireless mobile devices. In addition, hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (HEVs), and battery electric vehicles (e.g., gasoline vehicles, diesel vehicles, etc.) BEV) and electric vehicles (EV) are being proposed, and lithium secondary batteries are also attracting attention as a power source for such an internal combustion engine replacement vehicle.

Lithium secondary batteries are classified into lithium ion batteries and lithium polymer batteries according to the type of electrolyte, and are classified into a cylindrical shape, a square shape, or a pouch type according to the shape of the exterior material in which the electrode assembly is accommodated. Typically, an electrode assembly employed in a secondary battery has a jelly-roll form in which a positive electrode plate, a separator, and a negative electrode plate are stacked and wound up.

On the other hand, in recent years, there is a strong demand for extending the life of such a lithium secondary battery, and there is a demand for a technology that enables the performance of the battery to be maintained even when used for a long time.

When the secondary battery is used for a long time, stress caused by expansion and contraction of the electrode during charging and discharging is accumulated inside the electrode assembly, and when such stress accumulation exceeds a certain limit, permanent deformation of the electrode assembly occurs. This swelling phenomenon causes a problem in that the performance of the battery is rapidly deteriorated, and the safety of the battery is threatened due to an internal short circuit.

An aspect of the present invention provides a secondary battery with improved structure.

An aspect of the present invention provides a secondary battery with improved durability.

An aspect of the present invention provides a secondary battery with improved performance.

The secondary battery according to the spirit of the present invention includes an electrode assembly; A support case having a plurality of through holes formed on at least one surface thereof, the support case provided to surround the electrode assembly; It includes; a foam member positioned between the support case and the electrode assembly.

The foam member may be disposed between the at least one surface of the support case and the electrode assembly.

The foam member has a first state in which the electrolyte is absorbed; It may be provided to operate a second state in which the absorbed electrolyte is discharged by contracting from the first state.

The foam member is pressed by the expansion of the electrode assembly and is operated from the first state to the second state, and the expanded electrode assembly is discharged while the foam member is operated from the first state to the second state. It can absorb electrolyte.

It may further include an exterior material provided to surround the outer surface of the support case and configured to be elastically deformed.

The exterior material is pressurized by the electrolyte discharged from the foam member in the second state to form a supporting space in which the electrolyte is stored between the outer surface of the supporting case, and the exterior material is an electrode in which the electrolyte located in the supporting space is expanded. It may be configured to be elastically restored while moving to the assembly.

The foam member may be configured to contact each of the support case and the electrode assembly so that the electrode assembly is supported with respect to the support case.

The circumferential surface of the electrode assembly includes a first side and a second side wider than the first side, and the foam member has an inner surface in contact with the second side, and an outer surface of the second side in the support case. It may be arranged to contact the inner surface of the case facing the side.

The foam member may have a width of the inner surface smaller than that of the second side surface of the electrode assembly.

The support case may include a plurality of pressing protrusions formed on an inner surface thereof to contact the foam member, and a plurality of pressing protrusions configured to press the foam member together with the electrode assembly.

The plurality of pressing protrusions are disposed between the plurality of through holes, and may be disposed in the center of the inner surface of the support case.

A pair of the foam members is provided, and the support case includes: a first case covering one side of the electrode assembly and any one of the pair of foam members; And a second case that covers the other side of the electrode assembly and the other of the pair of foam members, and is detachably coupled to the first case.

The support case may include at least one of resin and metal.

The plurality of through holes may be uniformly disposed on the at least one surface of the support case.

A secondary battery according to the present invention includes an electrode assembly having a first side and a second side wider than the first side; A support case spaced apart from the second side surface and provided to surround the electrode assembly, the support case facing the second side surface and having a case inner surface formed with a plurality of through holes; And a foam member disposed between the inner surface of the case and the second side surface and absorbing the electrolyte, and configured to discharge the electrolyte depending on whether or not the electrode assembly is expanded.

The foam member is provided so as to be compressed by expansion of the electrode assembly so as to be contractible, and the electrolyte discharged by contraction of the foam member may be configured to flow to the expanded electrode assembly.

According to an aspect of the present invention, by improving the structure, it is possible to minimize performance degradation due to swelling.

According to an aspect of the present invention, the foam member and the support case can act as a buffer against external shocks, thereby improving the durability of the electrode assembly.

According to an aspect of the present invention, it is possible to increase the storage amount of the electrolyte, thereby increasing the life of the secondary battery.

1 is a front view of a secondary battery according to an embodiment of the present invention.
2 is an exploded perspective view of a secondary battery according to an embodiment of the present invention.
3 and 4 are cross-sectional views taken along line A-A' of FIG. 1 for a state change of a secondary battery according to an embodiment of the present invention.
5 and 6 are cross-sectional views taken along line A-A' of FIG. 1 for a state change of a secondary battery according to an embodiment of the present invention.
7 is a view showing the inner surface of the support case of the secondary battery according to an embodiment of the present invention.
8 and 9 are cross-sectional views taken along line A-A' of FIG. 1 for a state change of a secondary battery according to another embodiment of the present invention.

The embodiments described in the present specification and the configurations shown in the drawings are only preferred examples of the disclosed invention, and there may be various modifications that may replace the embodiments and drawings of the present specification at the time of filing of the present application.

In addition, the same reference numerals or reference numerals shown in each drawing of the present specification indicate parts or components that substantially perform the same function.

In addition, terms used in the present specification are used to describe the embodiments, and are not intended to limit and/or limit the disclosed invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification, but one or more other features. It does not preclude the presence or addition of elements, numbers, steps, actions, components, parts, or combinations thereof.

In addition, terms including ordinal numbers such as “first” and “second” used in the present specification may be used to describe various elements, but the elements are not limited by the terms, and the terms are It is used only for the purpose of distinguishing one component from other components. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term “and/or” includes a combination of a plurality of related listed items or any of a plurality of related listed items.

In addition, terms such as "~ unit", "~ group", "~ block", "~ member", and "~ module" may mean a unit that processes at least one function or operation. For example, the terms may refer to at least one hardware such as field-programmable gate array (FPGA)/application specific integrated circuit (ASIC), at least one software stored in a memory, or at least one process processed by a processor. have.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a front view of a secondary battery according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a secondary battery according to an embodiment of the present invention.

The secondary battery 1 may include an exterior material 5. The exterior material 5 may form the exterior of the secondary battery 1. An electrode assembly 10, a support case 20, and a foam member 40, which will be described later, may be located inside the exterior material 5. The exterior material 5 may be sealed so that the electrolyte solution therein is not discharged to the outside. The material of the exterior material 5 is not limited. For example, the exterior material 5 may include a can or a pouch.

The secondary battery 1 may include an electrode assembly 10.

The electrode assembly 10 may be formed in a state in which an anode (not shown), a cathode (not shown), and a separator (not shown) are formed as a layer to have a jelly-roll shape. An anode terminal 16 and a cathode terminal 18 are provided on one side (ie, the first side 11) or both sides of the electrode assembly 10 (ie, the first side 11 and the second side 12) Can be.

Since the electrode assembly 10 is formed by stacking or winding an anode, a cathode, and a separator while being folded into a plurality of layers, the anode terminal 16 and the cathode terminal 18 can be formed only in portions that are not wrapped by the separator. For example, if the electrode assembly has a shape similar to a rectangular parallelepiped structure, the anode terminal 16 and the cathode terminal 18 are both formed on the first side 11 of the rectangular parallelepiped, or the first side 11 and the first side It may be formed on the second surface 12 opposite to (11), respectively. The side surface of the electrode assembly 10 is provided to connect the first surface 11 and the second surface 12. The side surface of the electrode assembly 10 may be formed of four surfaces. The side surface of the electrode assembly 10 may include a first side surface 13 and a second side surface 14 that is wider than the first side surface 13. Since the electrode assembly 10 is formed in a rectangular parallelepiped shape, a pair of first and second side surfaces 13 and 14 may be provided, respectively.

The secondary battery 1 may include a support case 20.

The support case 20 may be provided to surround the electrode assembly 10. The support case 20 may be disposed such that at least a portion of the surface is spaced apart from the electrode assembly 10 by a predetermined distance. The support case 20 may include a plurality of through holes 26 penetrating the inner and outer surfaces thereof.

The support case 20 may be disposed to surround the side surface of the electrode assembly 10.

The support case 20 may be formed in a shape in which the electrode assembly 10 can be positioned inside. The support case 20 may include at least one of resin, metal, and ceramic having a certain strength. Specifically, the resin may be polypropylene or a resin having a higher melting point than that of polypropylene. Through this, the support case 20 can secure structural stability for the electrode assembly 10 located therein. That is, the support case 20 may improve the stiffness of the secondary battery 1 against an external force.

The support case 20 may be configured such that the electrode assembly 10 does not expand by more than a certain volume even though the internal pressure of the battery increases and expands when the secondary battery 1 is overcharged or stored at a high temperature. As a result, it is possible to alleviate physical damage to the electrode assembly 10 due to overdeformation, thereby preventing an internal short.

In addition, since the support case 20 is provided to surround the electrode assembly 10, it absorbs heat generated from the electrode assembly 10, thereby preventing the electrode assembly 10 from being excessively overheated. In addition, the support case 20 may prevent heat acting externally from being directly transferred to the electrode assembly 10.

The support case 20 may include a first case 21 and a second case 22 that is detachably coupled to the first case 21.

The first and second cases 21 and 31 include the first and second case bodies 22 and 32, and a plurality of coupling flanges 24 that are detachably coupled at both ends of the first and second case bodies 22 and 32. , 34).

The first and second case bodies 22 and 32 may be configured to face each of the pair of second side surfaces 14 of the electrode assembly 10. That is, the inner surfaces 22a and 32a of the first and second case bodies 22 and 32 may be disposed to face the second side 14 of the electrode assembly 10, respectively. The inner surfaces 22a and 32a of the first and second case bodies 22 and 32 and the second side surfaces 14 of the electrode assembly 10 may be disposed to be spaced apart by a predetermined distance G as shown in FIG. 3. The plurality of through holes 26 described above may be formed in the first and second case bodies 22 and 32.

A plurality of coupling flanges 24 and 34 may be provided at both ends of the first and second case bodies 22 and 32. The plurality of coupling flanges 24 and 34 may be provided with coupling portions 28 and 38 (refer to FIG. 3 ), respectively, so that the first and second cases 21 and 31 may be detachably coupled. In this embodiment, a pair of coupling flanges 24 (refer to Fig. 3) are provided at both ends of the first case body 22, and a pair of coupling flanges 34, Fig. 3 at both ends of the second case body 32 Reference) is provided, and facing coupling portions (28, 38, see FIG. 3) are configured to be detachably coupled to each other. However, the present invention is not limited thereto, and the coupling flanges 24 and 34 satisfy this when the first and second cases 21 and 31 are configured to be detachable.

The outer surface to which the plurality of coupling flanges 24 and 34 and the first and second case bodies 22 and 32 are connected may be provided to have a predetermined curvature as shown in R of FIGS. 2 and 3. Through this configuration, the external force applied to the secondary battery 1 can be dispersed, and thus durability of the secondary battery 1 can be improved. However, the present invention is not limited thereto, and the outer surface to which the plurality of coupling flanges 24 and 34 and the first and second case bodies 22 and 32 are connected may be formed in an angular shape.

The support case 20 may include a plurality of through holes 26.

A plurality of through holes 26 may be formed in the first and second case bodies 22 and 32. The plurality of through holes 26 may be configured to penetrate the inner and outer surfaces of the first and second case bodies 22 and 32. The electrolyte in the secondary battery 1 may move inside and outside the first and second case bodies 22 and 32 through the through hole 26.

The through hole 26 may carry the electrolyte when the electrolyte is injected into the lithium secondary battery 1. When the electrolyte is injected into the secondary battery 1, the electrolyte is injected into a space formed by the width of the through hole 26 and the thickness of the first and second case bodies 22 and 32, and the amount of the electrolyte injected by the corresponding space This can be increased. Loading of the electrolyte through the through hole 26 of the support case 20 increases the amount of electrolyte injected in the secondary battery 1, thereby improving the long-term reliability of the secondary battery 1.

The plurality of through holes 26 may be uniformly arranged on the first and second case bodies 22 and 32. Through this, the electrolyte in the secondary battery 1 may be evenly supported in the plurality of through holes 26.

The width of the plurality of through holes 26 may be more than half of the width of the first and second case bodies 22 and 32. The width of the plurality of through holes 26 is not limited, but since they are formed to be more than half the width of the first and second case bodies 22 and 32, it is possible to effectively support the electrolyte solution by the plurality of through holes 26. .

3 and 4 are cross-sectional views taken along line A-A' of FIG. 1 for a state change of a secondary battery according to an embodiment of the present invention.

The lithium secondary battery 1 includes an electrolyte that serves as a medium for moving lithium ions between an anode and a cathode inside an electrode assembly. The electrolyte is composed of a salt, a solvent, and an additive, and the salt acts as a passage through which lithium ions can pass, and the solvent is an organic liquid used to dissolve the salt. In addition, additives are substances added for certain purposes.

Here, as the battery is repeatedly charged and discharged according to the use of the lithium secondary battery 1, the electrolyte is gradually consumed. Furthermore, even when the lithium secondary battery 1 is exposed to a high temperature, the electrolyte is consumed by a chemical side reaction and gradually decreases. The reduction of the electrolyte solution adversely affects the life and safety of the lithium secondary battery 1, and the amount of electrolyte injected into the lithium secondary battery 1 affects the reliability of the lithium secondary battery 1. . Accordingly, the longer the electrolyte is injected into the lithium secondary battery 1, that is, as the electrolyte injection amount increases, the long-term reliability of the lithium secondary battery 1 is improved.

The secondary battery 1 may include a foam member 40. The foam member 40 is provided to absorb the electrolyte. As the foam member 40 absorbs the electrolyte, the secondary battery 1 can improve the electrolyte capacity. The foam member 40 may improve the reliability of the lithium secondary battery 1 by increasing the amount of the electrolyte solution injected into the lithium secondary battery 1 and extend the life of the lithium secondary battery 1.

The foam member 40 may be configured to absorb or discharge an electrolyte. The foam member 40 may be formed to be deformable. The foam member 40, like a sponge, is configured to absorb the electrolyte and discharge a certain amount of the electrolyte when the volume is reduced by being pressurized by an external force. The material of the foam member 40 is not limited, and any material without conductivity is satisfied.

A pair of foam members 40 may be provided, and may be disposed between the first and second cases 21 and 31 and the electrode assembly 10, respectively. Specifically, the foam member 40 may be positioned between the first and second case bodies 22 and 32 and the second side surface 14 of the electrode assembly 10. The first case 21 covers one side of the electrode assembly 10 and one of a pair of foam members, and the second case 22 covers the other side of the electrode assembly 10 and a pair of foam members. Covering the other one of the foam members may be detachably coupled to the first case 21. Through this, the foam member 40 and the electrode assembly 10 can be stably positioned inside the support case 20.

The initial state of the foam member 40 is the same as or thicker than the predetermined distance G, which is the distance between the inner surfaces 22a and 32a of the first and second case bodies 22 and 32 and the second side 14. I can. Through this, the foam member 40 having a larger volume than the space formed between the case bodies and the electrode assembly 10 can be disposed. Since the first and second cases 21 and 31 are provided to be separated from each other, even if the foam member 40 is formed thicker than a predetermined interval, the foam member 40 is formed with the first and second cases 21 and 31 and the electrode assembly. (10) Can be assembled to be located between. Through this, it is possible to increase the amount of electrolyte absorbed by the foam member 40 and improve the buffering effect.

The foam member 40 may operate in a first state 40a in which the electrolyte is absorbed and a second state 40b in which the absorbed electrolyte is discharged by contracting from the first state 40a.

The foam member 40 may maintain a state in which the electrolyte is absorbed as shown in FIG. 3 in the first state 40a. When the secondary battery 1 is used for a long time, the electrode assembly 10 expands due to stress accumulation. The foam member 40 is pressed by the expanded electrode assembly 10b (refer to FIG. 4) when expansion occurs due to the swelling of the electrode assembly 10 as shown in FIG. 4, and the second in the first state 40a While transforming into the state 40b, the absorbed electrolyte may be discharged.

As the foam member 40 is transformed from the first state 40a to the second state 40b, the discharged electrolyte may be absorbed by the expanded electrode assembly 10b. That is, the electrode assembly 10 expands, but since the electrolyte in the electrode assembly 10 is constant or decreased, the specific gravity of the electrolyte in the expanded electrode assembly 10b decreases. Therefore, the electrolyte discharged due to the expansion of the electrode assembly 10 and the shrinkage deformation of the foam member 40 is moved and absorbed by the expanded electrode assembly 10b as shown in FIG. 4A, thereby deteriorating the performance of the electrode assembly 10 Can be minimized.

The foam member 40 may be provided so that the inner and outer surfaces thereof contact the inner surfaces 22a and 32a of the first and second case bodies 22 and 32 and the second side 14 of the electrode assembly 10, respectively. . The foam member 40 is disposed between the first and second cases 21 and 31 and the electrode assembly 10, so that the electrode assembly 10 can be stably positioned in the secondary battery 1. That is, the foam member 40 is provided so that the electrode assembly 10 is stably supported with respect to the support case 20. Through this, it is possible to prevent the external impact of the secondary battery 1 from being transmitted to the electrode assembly 10. That is, since the foam member 40 is formed of a material having deformable elasticity, it may function as a damper for absorbing external shock.

The foam member 40 may be located between the inner surfaces 22a and 32a of the first and second case bodies 22 and 32 in which a plurality of through holes 26 are formed and the second side 14 of the electrode assembly 10. I can. The foam member 40 is in contact with the inner surfaces 22a and 32a of the first and second case bodies 22 and 32 in which a plurality of through holes 26 are located, so that the foam member 40 is formed of the electrode assembly 10. When the expanded volume is large, at least a portion of the body may be inserted into the plurality of through holes 26. That is, the space formed by the plurality of through holes 26 may function as a space for preventing excessive contraction of the foam member 40.

The outer surface 42 of the foam member 40 may cover a plurality of through holes 26 uniformly formed in the first and second case bodies 22 and 32. With this configuration, the foam member 40 may distribute a force pressed to the inner surface of the foam member 40 by the expansion of the electrode assembly 10 over the entire area of the foam member 40. Through this, the contraction operation of the foam member 40 may occur smoothly, and the foam member 40 may be uniformly pressed against the entire area. In addition, the electrolyte absorbed by the foam member 40 may be uniformly discharged over the entire area.

The volume of the foam member 40 contracted from the first state 40a to the second state 40b may be the same as the volume increased as the electrode assembly 10 is expanded (10b). That is, since the foam member 40 is configured to be elastically deformable, the expanded electrode assembly 10b can be contracted as much as it is expanded. Through this, the load due to the expansion of the electrode assembly 10 can be prevented from being transferred to the support case 20 located outside the electrode assembly 10.

The foam member 40 may have an inner surface that is smaller than that of the second side 14 of the electrode assembly 10. Through this configuration, it is possible to prevent the occurrence of poor sealing due to interference by the foam member 40 in the formation and sealing of the exterior material 5. However, the area of the foam member 40 is not limited.

As an example, the width of the foam member 40 may be larger than the width of the second side 14 of the electrode assembly 10 and smaller than the inner surfaces 22a and 32a of the case bodies 22 and 32. have. Through this, the foam member 40 can support the electrode assembly 10 with respect to the support case 20 more stably, and can carry a larger amount of electrolyte.

An operation of the secondary battery 1 according to an embodiment of the present invention will be described with reference to FIGS. 3 and 4.

As shown in FIG. 3, the foam member 40 is provided to absorb a certain amount of electrolyte in the first state 40a. Thereafter, as shown in FIG. 4, the electrode assembly 10 is expanded to press the foam member 40. The foam member 40 is pressed by the expanded electrode assembly 10b, operates in the second state 40b, and discharges the absorbed electrolyte, and the discharged electrolyte is the expanded electrode assembly 10b as shown in FIG. 4A. ) Is absorbed.

5 and 6 are cross-sectional views taken along line A-A' of FIG. 1 for a state change of a secondary battery according to an embodiment of the present invention.

The exterior material 5 may be provided to be elastically deformable. The exterior material 5 may be elastically deformed by being pressed by the electrolyte solution from the foam member 40 within a range in which permanent deformation does not occur. The exterior material 5 may be elastically deformed to form a supporting space 7 between the support case 20 and the support case 20.

When the electrode assembly 10 expands rapidly, the rate of absorption of the electrolyte into the expanded electrode assembly 10 may be less than that of the electrode assembly 10. In this case, while the foam member 40 is pressurized in the second state 40b, the discharged electrolyte moves through the through hole 26 of the support case 20 to press the exterior material 5. The exterior material 5 may be pressurized by the electrolyte discharged from the foam member 40 in the second state 40b to form a supporting space 7 in which the electrolyte is stored between the outer surface of the support case 20 and between. Some of the electrolyte discharged from the foam member 40 is absorbed by the expanded electrode assembly 10b as shown in B1 of FIG. 5, and a part not absorbed by the expanded electrode assembly 10b is an exterior material ( It can be moved to the supporting space 7 formed by 5).

The electrolyte in the supporting space 7 may move as shown in B3 of FIG. 6 over time and may be absorbed by the expanded electrode assembly 10b. In this process, the exterior material 5 can be operated in its original state by the elastic return force. That is, as the electrolyte solution is continuously absorbed from the expanded electrode assembly 10b, the electrolyte located in the supporting space 7 passes through the through hole 26 of the support case 20, and the expanded electrode assembly 10b as shown in B3. While moving to, the exterior material 5 is elastically restored. The elastically restored exterior material 5 may be positioned in an initial state by contacting the outer surface of the support case 20.

Hereinafter, a secondary battery according to another embodiment of the present invention will be described.

7 is a view showing an inner surface of a supporting case of a secondary battery according to an embodiment of the present invention, and FIGS. 8 and 9 are A-A' of FIG. 1 for a state change of a secondary battery according to another embodiment of the present invention. It is a cross-sectional view.

The support case 20 may include at least one pressing protrusion 27 and 37.

At least one pressing protrusion 27 and 37 may be configured to protrude from the inner surfaces 22a and 32a of the support case 20. The at least one pressing protrusion 27 and 37 may be configured to contact the foam member 40 on the inner surfaces 22a and 32a of the support case 20. At least one pressing protrusion 27 and 37 may be provided to press the foam member 40 together with the electrode assembly 10b that expands as shown in FIG. 9.

At least one pressing protrusion (27, 37) is configured to pressurize or support the outer surface 42 of the foam member 40, and the electrode assembly 10 presses the inner surface 41 of the foam member 40 due to expansion At the time, the electrolyte solution can be effectively discharged from the foam member 40. That is, the pressing protrusions 27 and 37 may facilitate the discharge of the electrolyte during the process of the foam member 40 operating from the first state 40a to the second state 40b.

A plurality of pressing protrusions 27 and 37 may be provided, and may be positioned between a plurality of through holes. In this embodiment, the plurality of pressing protrusions 27 and 37 are illustrated to be disposed in the center of the inner surface of the support case among the plurality of through holes, but are not limited thereto. The plurality of pressing protrusions 27 and 37 may be uniformly arranged as a whole on the inner surface of the support case, and the arrangement and number thereof are not limited.

The pressing protrusions 27 and 37 may be configured such that at least a part of the outer surface thereof includes a curved surface. Specifically, ends of the pressing protrusions 27 and 37 may be formed in a curved surface. Through this configuration, even when the electrode assembly 10 is excessively expanded, it is possible to prevent the electrode assembly 10 from being damaged by contacting the pressing protrusions 27 and 37.

In the above, specific embodiments have been illustrated and described. However, it is not limited only to the above-described embodiments, and those of ordinary skill in the technical field to which the invention pertains will be able to perform various changes without departing from the gist of the technical idea of the invention described in the following claims. .

1: secondary battery 10: electrode assembly
11: first side 12: second side
13: first side 14: second side
16: anode terminal 18: cathode terminal
20: support case 21, 31: first, second case body
24, 34: coupling flange 26: through hole
40: foam member 40a: first state
40b: second state

Claims (16)

Electrode assembly;
A support case having a plurality of through holes formed on at least one surface thereof, the support case provided to surround the electrode assembly;
Secondary battery including; a foam member positioned between the support case and the electrode assembly. The secondary battery of claim 1, wherein the foam member is disposed between the at least one surface of the support case and the electrode assembly. The method of claim 1, wherein the foam member,
A first state in which the electrolyte is absorbed;
A secondary battery provided to operate in a second state in which the absorbed electrolyte is discharged by contracting from the first state. The method of claim 3, wherein the foam member is pressed by expansion of the electrode assembly to operate from the first state to the second state,
The expanded electrode assembly absorbs the discharged electrolyte while the foam member is operated from the first state to the second state. The secondary battery according to claim 4, further comprising an exterior material provided to surround the outer surface of the support case and configured to be elastically deformed. The method of claim 5, wherein the exterior material is pressurized by the electrolyte discharged from the foam member in the second state to form a supporting space in which the electrolyte is stored between the outer surface of the supporting case, and the exterior material is located in the supporting space. A secondary battery configured to be elastically restored while the electrolyte is moved to the expanded electrode assembly. The secondary battery of claim 1, wherein the foam member is configured to contact the support case and the electrode assembly, respectively, so that the electrode assembly is supported with respect to the support case. The method of claim 1, wherein the circumferential surface of the electrode assembly includes a first side surface and a second side surface wider than the first side surface,
The foam member is a secondary battery disposed such that an inner surface thereof contacts the second side surface, and an outer surface thereof contacts an inner surface of the case facing the second side surface in the support case. The secondary battery of claim 8, wherein the foam member has an inner surface area smaller than an area of the second side surface of the electrode assembly. The method of claim 4, wherein the support case,
And a plurality of pressing protrusions formed on an inner surface thereof to contact the foam member, the plurality of pressing protrusions configured to press the foam member together with the electrode assembly. The method of claim 10,
The plurality of pressing projections,
A secondary battery disposed between the plurality of through holes and disposed in the center of the inner surface of the support case. The method of claim 1,
The foam member is provided with a pair,
The support case includes: a first case covering one side of the electrode assembly and any one of the pair of foam members;
And a second case that covers the other side of the electrode assembly and the other one of the pair of foam members, and is detachably coupled to the first case. The secondary battery of claim 1, wherein the support case includes at least one of a resin and a metal. The secondary battery of claim 1, wherein the plurality of through holes are uniformly disposed on the at least one surface of the support case. An electrode assembly having a first side surface and a second side surface wider than the first side surface;
A support case spaced apart from the second side surface and provided to surround the electrode assembly, the support case facing the second side surface and having a case inner surface formed with a plurality of through holes;
And a foam member disposed between the inner surface of the case and the second side surface and absorbing the electrolyte, wherein the foam member is provided to discharge the electrolyte depending on whether the electrode assembly is expanded. The secondary battery of claim 15, wherein the foam member is provided to be compressed and contracted by expansion of the electrode assembly, and the electrolyte discharged by contraction of the foam member flows to the expanded electrode assembly.

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